We are investigating the clinical applications of a new 3-D viewing device for computed tomographic scans that allows a physician to examine multiple sections simultaneously with each section registered properly in all three dimensions. Several people can view the image at the same time and there is no need for special glasses. Images seen on the device exhibit both stereoscopic and motion parallax cues characteristic of a real three dimensional object. The resulting depth effects appear to be useful in complex anatomical relationships and in distinguishing pathological pathological entities from normal structures. We plan to continue our the head and abdomen exhibit very realistic depth cues which are frequently to begin a new series of experiments specifically oriented to regular use anatomical landmarks. Graphical overlays (line drawings) are especially will be initiated which are designed to reduce the incidence of chronic or structures having internal voids (cerebral ventricles, bile ducts) are boundaries, more precise construction of field collimator blocks and 3-D grayscale for the image to be comprehensible. We should be able to improve studies of the eye's ability to detect and interpret detail in 3-D response to the volumetric images produced by this device is obtained. We plan to continue these investigations by conducting experiments to quantitatively assess an observer's ability to detect the presence of dark voids interior to luminous solids from low contract volumetric images. We will also begin regular use of a 3-D viewer in our clinical area to determine which types of diagnostic examinations benefit most from 3-D display.